<div class="gmail_quote">On Thu, May 26, 2011 at 13:46, Bartłomiej W <span dir="ltr"><<a href="mailto:bartlomiej.wach@yahoo.pl">bartlomiej.wach@yahoo.pl</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;">
That helped.<br><br>I am also wondering about SEQ and MPI matrices, do they differ more than just in way of allocating data? When I run a small problem on 2 processes on single machine, it slows down greatly if I use <br>
<br><span style="font-style:italic">MatCreateMPIAIJ(PETSC_COMM_WORLD,PETSC_DECIDE,PETSC_DECIDE,n,n,5,PETSC_NULL,5,PETSC_NULL,&L);</span><br style="font-style:italic"><br>As I get mallocs during mat assembly while o_nz and d_nz are set to 5 where 5 is max nonzeros per whole row. I also get stash:0 assuring that values are set by correct process.</blockquote>
</div><br><div>Your preallocation is either incorrect or it is getting lost. Try MAT_NEW_NONZERO_ALLOCATION_ERR</div><div><br></div><div><a href="http://www.mcs.anl.gov/petsc/petsc-as/snapshots/petsc-dev/docs/manualpages/Mat/MatSetOption.html">http://www.mcs.anl.gov/petsc/petsc-as/snapshots/petsc-dev/docs/manualpages/Mat/MatSetOption.html</a></div>